Safety device for drill bit



July 30, 1957 F. GREss SAFETY DEVICE FOR DRILL BT Filed sept. 3, 1954 INVENTOR ATTORNEYS United SAFETY DEVICE FOR DRILL BIT Frank Gress, Prosser, Wash.

Application September 3, 1954, Serial No. 454,036

1 Claim. (Cl. Z55-61) This invention pertains to a safety device for a drill bit to be used on all types and sizes of ground engaging drills and the like.

It is a primary object of this invention to provide a safety device for a drill bit of the kind to be more particularly described hereinafter having a cup to catch the rocks and limits the passage of smaller rocks through the device which drop down from above to prevent the drill bit from jamming and locking during its operation.

Another object of this invention is to provide a safety device for a drill bit having a member on the lower end of the drill rod adjacent to the bit thereon to keep the wall of the hole being drilled clear and clean while drilling through clay and thereby preventing the drill bit from jamming or locking.

A further object of this invention is to provide a safety device for a ground engaging drill bit slightly smaller than the hole being bored to permit the free ow of air between the drill bit and bored hole, there being small holes or apertures in the device adjacent the outermost edge thereof to prevent coarse grain from collecting in the device.

Other and further objects and advantages of the invention will be hereinafter described and the novel features thereof dened in the appended claim.

In the drawings:

Fig. 1 is a fragmentary longitudinal section, partly broken away, through a drill bit safety device constructed according to an embodiment of my invention.

Fig. 2 is a transverse section taken on the line 2 2 of Fig. 1.

Fig. 3 is a perspective view of the cup of the safety device showing the bottom wall thereof.

In the use of drill bits for drilling holes vertically through the ground both when the ground is hard or when the ground is primarily of clay, a safety device has been provided for keeping the drill bit of the drilling device clear from obstructing material during its use and operation.

To accomplish this keeping of the drill bit clear from obstructions resulting from the drilling use of the drill bit, there is provided herein a safety device for attachment to the lowermost end of the drilling steel and primarily to the lower end of the steel shank 11.

In the formation of the safety device there is provided an outwardly extending shoulder 14 on the lower end oi the steel shank 11 which extends radially and laterally outwardly on the enlarged end 12 of the steel shank 11 as clearly noted in Fig. 1 of the drawings.

A downwardly extending tapered pin 15 is forme-d integral with the steel shank 11, co-axial therewith, the lowermost end of the tapered threaded pin 15 extending downwardly from and being in spaced relation below the shoulder 14.

For the clearing of the drill bit attached to the pin 15 there is provided a longitudinally extending passageway 16 through the steel shank 11 substantially on the axis thereof. The use of the passageway 16 through the steel 11 is for the passage therethrough of air for the purposes and use to be more particularly described hereinafter.

The safety device 10 includes primarily a cup 17 secured to the shank 11 of the steel having the outer edges thereof concentric to the axis of the steel, the cup 17 having a bottom wall 18 with an enlarged opening 19 near the center thereof for receiving therethrough the pin 1S at the time of the assembly of the steel with the safety device. Further apertures 20 are also formed in the bottom wall 18 spaced outwardly from the screw receiving openings 19 which apertures are provided for the free passage therethrough of air about the drill bit 22 during the use and operation of the drill bit. The apertures 20 in the cup 17 are of such a size as to prevent coarse grit from collecting in the cup.

The cup 17 is stamped from a single piece of sheet material and besides having the bottom wall 13 transversely of the steel shank 11 has a cylindrical side wall 29 which rises from, and extends upwardly from the bottom wall 1S.

The drill bit 22 threadably engaged on the pin 15 has a ared cutting edge 24 spaced downwardly below the extreme lower side of the shoulder 14 and the pin 15 for cutting a regular type of bore in the ground.

There is provided a protuberance 25 extending axially of the drill bit 22 interiorly of the flared cutting edge 24, the protuberance 25 having inclined passageways 26 coming together at the axis of the steel with the passageway 30 in the protuberance 2S. The upper end of the passageway 30 is located in direct registration with the lower end of the passageway 16 through the shank of the steel. The space above the cutting edges 24 of the drill bit 22 is so located that the apertures 2t? of the bottom wall of the cup 17 are in direct communication therewith.

The body or shank Z7 of the drill bit 22 has an outer face or edge 2S at the upper end thereof facing upwardly of the assembly and iiushly engaging the lower side of the bottom wall 1S of the cup so that the center portion of the bottom wall 1S is held between the downwardly facing shoulder 14 of the enlarged end 12 of the shank 11 and the face 2S when the drill bit 22 is properly engaged with the screw 1S of the steel shank.

In the use and operation of the safety device for a drill bit 22 the air discharged from openings 25 will rise upwardly, carrying therewith the finely ground particles. These particles will pass between cup 17 and the wall of the hole and the ne material will also pass through the holes 20. The diameter of the bottoni wall 18 is a slight bit less than the diameter of the flared cutting edge 24 so that the flared cutting edge 24 will bore the earth independently of the .cup 17, the cup being provided only for catching all small rocks and preventing their passage to the drill bit thereby preventing the bit from jamming and locking due to such obstructions. The cup will also keep the wall of the hole clear and clean while drilling through clay since the cup is just a little smaller, in diameter, than the hole and provides for the air passage between the cup and the wall being drilled.

While the speciiic details of one embodiment of this invention have been herein shown and described, the invention is not conned thereto as changes and alterations may be made without departing from the spirit and scope thereof as defined in the appended claim.

I claim:

A safety device for a drill bit comprising in combination, a drill steel shank having an enlarged end with an integral depending coaxial downwardly tapered threaded pin of lesser diameter than the end of said shank, and having a central bore therethrough, the end of said shank surrounding said pin forming a downwardly facing *Y A Y:2,801,079

threaded on said pin, the upper face of said bit around said bore confronting said, shoulder, a cup having an apertured bottorrrwall` and an annular'outer side Wall, saidbottomy Wall seating against said shoulder with vits aperture surrounding said pin, said bottom Wall being clamped against said shoulder by theupper face of said bit when said bit is threaded Von said pin, said annular side Wall being of less diameter than the diameter of said bit, and terminating above but closely adjacent the top ofsaid enlarged end of said shank, the top of said cup being open, said bit having lateral openings communicating with said bore and said bottom wall ofisaid cup 4 i having holes extending therethrough between the outer periphery of said enlarged end and the insidegof said annular Wall. 5

References Cited in the file of this patent UNITED STATES PATENTS 47,805 Dickey May 23, 1865 642,587 Davis Feb. 6, 1900 1,525,235 Hansen Feb. 3, 1925 FOREIGN PATENTS 500,664 Great Britain Feb. 14, 1939 Wea-ff 

